Centering tool

ABSTRACT

A work object centering tool having a socket mount with a conical exterior surface defining a longitudinal axis, an elongated rod secured on the mount in alignment with the axis, a slide member received on the rod, three arms pivotally secured on the slide member, an extension individually borne by each arm in substantial right angular relation thereto, and springs interconnecting the arms tensionably to retain the arms in contact with the surface of the mount over a predetermined path of movement with the remote ends of the extensions in a plane substantially normal to the axis of the mount and approximately 120* apart in the plane.

iJnited States Patent [19] Brooks CENTERING TOUL Inventor: Daryl G.Brooks, Fresno, Calif.

Porta-Tool, incorporated, Clovis, Calif.

Filed: June 4, 1973 Appl. No.1 366,865

Assignee:

References Cited UNITED STATES PATENTS ll/1929 Appleton 408/75 Mahl33/191 Holleman 408/82 11] 3,836,277 Sept. 17, 1976 PrimaryExaminer-Francis S. Husar Attorney, Agent, or Firm-Huebner & Worrel [57] ABSTRACT A work object centering tool having a socket mount with aconical exterior surface defining a longitudinal axis, an elongated rodsecured on the mount in alignment with the axis, a slide member receivedon the rod, three arms pivotally secured on the slide member, anextension individually borne by each arm in substantial right angularrelation thereto, and springs interconnecting the arms tensionably toretain the arms in contact with the surface of the mount over apredetermined path of movement with the remote ends of the extensions ina plane substantially normal to the axis of the mount and approximately120 apart in the plane.

7 Claims, 6 Drawing Figures cENranrNo TOOL BACKGROUND OF THE INVENTIONThe present invention relates to a centering tool and more particularlyto such a tool which permits immediate and precise centering of acylindrical bore with respect to a selected reference point. The tool isadapted for use with the applicants invention disclosed in his patentapplication entitled Boring Machine submitted concurrently herewith.

Centering tools have long been employed in industry to center a workobject, such as an internal combustion engine cylinder, relative to awork performing tool, such as a boring machine. As in the case ofrefinishing the cylindrical bore of an engine cylinder, precision withinquite narrow tolerances is essential in order to produce a finishedproduct of usable quality. For this reason, prior art centering toolsare commonly of relatively complex construction requiring ratherinvolved and time consuming manipulation in order to insure the requiredprecision. The delay attendant with such manipulation of the centeringtools makes their use onerous and expensive, but nonetheless essential.

An additional deficiency encountered with the use of conventionalcentering tools is directly related to their relatively complexconstruction. After long periods of use, such centering tools begin tolose the precision with which they can be employed. Particularly wherescrew threaded adjustments, slide adjustments and the like are utilized,a certain degree of give or play begins imperceptively to develop insuch structures after prolonged use. Since such play develops quiteslowly, it may not be noticed until well after adverse results areproduced.

Therefore, it has long been recognized that it would be desirable tohave a centering tool which is of extremely simplified constructionaffording an ease of operation unattainable with conventional centeringtools and which can be employed with dispatch to center a work objectrelative to a work performing tool within quite narrow and acceptabletolerances insuring a long operational life without danger ofprogressive variation in the results produced.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object ofthe present invention to provide an improved centering tool.

Another object is to provide such a tool which is of extremelysimplified construction.

Another object is to provide such a tool which can rapidly be mounted,operated to center the work object relative to the work performing tool,and removed without onerous and time-consuming adjustment.

Another object is to provide such a tool which has a structure whichminimizes the danger of the development of precision reducing play inthe operative elements thereof.

Another object is to provide such a tool which is specifically adaptedto center the cylindrical bore of an internal combustion engine cylinderwith respect to the work end of a boring machine.

Another object is to provide such a tool which is adapted for use withthe applicants boring machine for which a patent has been applied.

A further object is to provide such a tool which is of minimum expenseto manufacture and therefore to purchase.

Still further objects and advantages are to provide improved elementsand arrangements therefore in a device for the purposes described whichis dependable, economical, durable and fully effective in accomplishingits intended purposes.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a side elevation of thecentering tool of the present invention shown mounted on the work end ofa boring machine in centering relation to an engine cylinder.

FIG. 2 is a somewhat enlarged side elevation of the centering tool withportions thereof broken away to expose the interior constructionthereof.

FIG. 3 is a horizontal section taken from a position indicated by line33 in FIG. 2.

FIG. 4l is a horizontal section taken from a position indicated by line4l4l in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawing, the orienting or centering tool of the present invention isgenerally indicated by the numeral III. The centering tool is adapted tobe employed on a wide variety of types of work performing tools.However, as shown in FIG. I the centering tool is mounted on a boringmachine, generally indicated by the numeraI II, disclosed in theapplicants patent application entitled Boring Ma chine submittedconcurrently herewith. As disclosed in that application, the boringmachine has a horizontal base plate I2 mounting a shaft bearing I3therein. A tool mounting shaft 14!- is received in the bearing forrotational and endward movement. The shaft has a work end 15 in which islaterally adjustably received a boring tool 16 having a cutting edge I7.A reference point in the form of a frustoconical projection I8 isaffixed on the work end of the shaft in alignment with the axis ofrotation of the shaft. A cylinder support plate I9 is secured on thebase plate and has a recess 20 therein of a predetermined sizeconcentric to the shaft. A pair of slide plates 2I are adjustablysecured on the support plate for individual movement to and from therecess. A pressure applying plate 22, fragmentarily shown in FIG. I, isborne by the machine for vertical movement to and from the slide plates.The pressure applying plate has a recess 23 which is positionable withthe plate in approximate vertical alignment with recess 20.

An internal combustion engine cylinder is generally indicated at 30 inFIG. I shown in position for boring on the boring machine II. Thecylinder has a head end 3I and an opposite block end 32. The cylinderhas a peripheral seat 33 adjacent to the head end and a periph eral seat34 adjacent to the block end. The cylinder also has an interiorcylindrical surface 35 defining a cylindrical bore 36 extendinglongitudinally through the cylinder to communicate with the oppositeends thereof.

The centering tool III has a cone: or releasible mount 40, preferablyconstructed of hardened steel, having a frustoconical cam surface II anddefining a longitudinal axis indicated at 42 for illustrativeconvenience. The mount has a broad end 43 and an opposite narrow end 44.The peripheral juncture of the broad end and the cam surface preferablyhas a beveled edge 45, as shown in FIG. 1. A frustoconical bore orsocket 46 extends inwardly of the mount from the broad end thereof inalignment with the longitudinal axis of the mount. The dimensions of thesocket preferably precisely correspond to the dimensions of theprojection 18 of the boring machine 11. Alternatively, the dimensions ofthe socket can be such as to permit pressure fitting of the socket aboutthe projection. In any event, the size and shape of the socket are suchthat when the mount is received on the projection 18, the mount issecurely retained in axial alignment with the axis of rotation of theshaft. It will, of course, be seen that the mount can similarly beemployed to engage a similar structure of any work performing tool forperformance of the centering operation. Furthermore, any suitablestructure can be employed for connection of the centering tool to theparticular work performing tool being employed without departing fromthe invention.

An elongated cylindrical rod 50, having opposite ends 51, is integrallymounted on the narrow end 44 of the releasible mount 40 by one of itsends in alignment with the longitudinal axis of the mount. A suitablehandle 52 is affixed on the remote end of the rod. The handle is of aconfiguration presenting a striking surface 53 facing the mount at theopposite end of the rod.

A carrier or slide member 60, having a longitudinal cylindrical bore 61of a diameter corresponding to that of the rod 50, is slidably receivedon the rod so that the rod extends through the cylindrical bore thuspermitting movement of the member along the rod between the strikingsurface 53 of the handle 52 and the narrow end 44 of the mount 40. Theslide member has a striking end 62 most closely adjacent to the strikingsurface of the handle and an opposite flange portion 63 most closelyadjacent to the mount. The flange portion extends outwardly of the slidemember substantially normal to the rod. The slide member, intermediateits striking end and flange portion, preferably has a roughenedcylindrical surface 64.

As perhaps best shown in FIG' 3, three pivotal connections are borne bythe flange portion 63 of the slide member 60 and are generally indicatedby numerals 70. Each of the pivotal connections has a slot 71 extendingthrough the peripheral flange 63 and communicating with the cylindricalbore 61, as shown in FIG. 2. As shown in FIG. 4 for illustrativeconvenience, the slots individually define longitudinal, central planes72 which intersect in coincidence with the longitudinal axis 42 of thereleasible mount 40. The planes radiate from the longitudinal axisspaced 120 apart, as shown therein. Each of the pivotal connections hasa counterbore 73 extending into the flange portion of the slide memberin tangentially spaced relation to the rod 50 and extending through itsrespective slot normal to the central plane thereof. Each counterborehas a screw threaded portion 74 adjacent to its innermost end. A screwthreaded pivot pin 75 is individually received in each of the bores andscrew threadably engaged in the threaded portion 74 of the bore.

An arm 80 is individually, pivotally mounted on the pivot pin 75 of eachpivotal connection 70. Each arm has a control portion 81, havingopposite ends 82, pivotally mounted on its respective pivot pin adjacentto one of its opposite ends, as shown in FIG. 2. A finger or lateralextension 83 is mounted on the other end of each arm extending outwardlyfrom and substantially normal to the rod. Each extension has a contactpoint 84. The end of the control portion of each arm mounting theextension has a cam edge 85 opposite to the extension. The arms areidentical so that the control portions of the arms are the same lengthand configuration and the distances between the cam edges and thecontact points of the arms are identical. The control portions of thearms are interconnected by tension springs 86, as best shown in FIG. 4.The tension springs resiliently maintain the cam edges of the arms inengagement with the mount 40 or rod depending upon the position of theslide member 60.

OPERATION The operation of the described embodiment of the subjectinvention is believed to be clearly apparent and is briefly summarizedat this point. As described in greater detail in the applicantspreviously identified patent application on the boring machine 1 1,rough positioning of the engine cylinder 30 on the machine is readilyaccomplished. The work end 15 mounting the boring tool 16 is retractedto the position shown in FIG. 1. The slide plates 21 are loosened andpositioned so as to permit receipt of the block end 32 of the cylindertherebetween with the peripheral seat 34 received gravitationallyagainst the slide plates. The pressure applying plate 22 is pivoteddownwardly to engage the peripheral seat 33 adjacent to the head end ofthe cylinder.

Subsequently, the centering tool 10, being held by the handle 52 andwith the slide member retracted to the position shown in FIG. 2, isinserted through the recess 23 of the pressure applying plate 22 andinto the cylindrical bore 36 of the cylinder 30. The tool is directed sothat the projection 18 of the shaft 14 is received in the frustoconicalsocket 46 of the releasible mount 40 and firmly seated therein, as shownin FIG. 1. Thus, the longitudinal axis 42 of the releasible mount andtherefore of the elongated cylindrical rod 50 is precisely axiallyaligned with the axis of rotation of the shaft, as previously described.

The slide member 60 is then grasped by its roughened cylindrical surface64 and directed toward the releasible mount. As the cam edges 85 of thearms contact the mount 40, they are directed outwardly along thefrustoconical cam surface 41 of the mount with the tension springs 86maintaining the cam edges resiliently in contact with the cam surface.As the slide member continues to be motivated along the rod in thedirection of the mount, the arms are forced away from the longitudinalaxis 42 of the mount so that the contact points 84 of the'lateralextensions 83 are similarly directed outwardly. Assuming the cylindricalbore 36 is not already accurately centered, one or two of the contactpoints engage the cylindrical surface 35 as movement of the slide memberis continued. During continuation of the movement, the contact pointsengaging the surface move the cylinder 30 in that direction until thecontact points of all three arms engage the cylindrical surface. Whenthis occurs the slide member is thereby restrained from further movementtoward the mount and the operator is thus informed that the cylindricalbore 36 is positioned in precise axial alignment with the longitudinalaxis of the mount and therefore the axis of rotation of the shaft.

The slide plates 21 of the boring machine 11 are then motivated towardeach other to engage the cylinder 30 and are then locked in position soas to retain the cylindrical bore 36 in the precisely centered position.The centering tool is removed from the projection 18 either by directlypulling upwardly on the handle 52 or, particularly where the fit on theprojection is snug, by grasping the slide member 60 and motivating ittoward the handle until the striking end 62 of the member strikes thestriking surface 53 of the handle. The resultant jolt is sufficient torelease the mount 40 from the projection and allow the tool to bewithdrawn from the cylinder. This method of removal also allows thecontact points 84 to be retracted from the cylindrical surface 35 of thecylinder so as to avoid scoring during removal.

Therefore, the centering tool of the present invention is of asimplified and reliable construction not heretofore achieved inconventional centering tools thus maximizing the ease and speed withwhich the tool can be operated while minimizing the risk of error in theresults produced.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the illustrative detailsdisclosed.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

l. A tool for positioning a work object, having an axis, with said axisdisposed in a predetermined attitude with respect to a reference member,the tool comprising an elongated rod having opposite ends; a mount,having a cam surface and a reference member engaging socket defining anaxis, secured on one end of the rod; a slide member received on the rod;at least three angled arms pivotally suspended from the slide membertoward the mount; said arms being mounted for movement in planeslaterally disposed with respect to the rod, said planes intersecting incoincidence with the axis of the socket; and means for resilientlyretaining the arms in engagement with the cam surface.

2. The tool of claim 1 in which each arm has a control portion, havingopposite ends, pivotally secured on the slide member at one of its endsand mounting a lateral extension at the other of its ends.

3. The tool of claim 2 in which the resilient means includes tensionspring interconnecting the arms.

4. The tool of claim 3 in which a handle is borne by the rod on the endthereof remote from the mount, said handle having a striking surfacefacing the slide memher.

5. A tool for centering the cylindrical bore of an internal combustionengine cylinder relative to the work end of a boring machine, the toolcomprising a releasible mount defining a longitudinal axis, said mounthaving a work end receiving socket and a conical exterior surface inaxial alignment with the longitudinal axis; an elongated rod secured onthe mount remote from the socket and in axial alignment therewith; ahandle affixed on the end of the rod remote from the mount; asubstantially cylindrical slide member received on the rod intermediatethe mount and the handle; three pivotal connections mounted on the slidemember defining a plane substantially normal to the rod, the connectionsbeing spaced approximately in said plane equidistant from the rod; anarm individually fastened on each connection; an extension borne by eacharm remote from its respective connection in right angular relationthereto; and tension springs interconnecting the arms to urge themtoward the axis of the mount.

6. A tool for centering a cylinder concentrically about a predeterminedaxis comprising means for supporting the cylinder for adjustablemovement relative to the axis while constraining the cylinder toparallelism therewith, a cone mounted concentrically of the axis, acarrier mounted for reciprocal movement along the axis toward and fromthe cone, substantially identical arms pivotally mounted on the carrierin substan' tially equally spaced relation about the axis for move mentinwardly toward the axis and outwardly therefrom having portionsengageable with the cone and fingers outwardly extended for engagementwith the cylinder, and resilient means urging the fingers inwardly toward the axis whereby movement of the arms endwardly of the conecorrespondingly extends and retracts the fingers to and from cylinderengagement.

7. A tool for centering a cylinder concentrically about a predeterminedaxis comprising means for supporting the cylinder in a plane normal tothe axis for adjustable movement in the plane with the cylinder parallelto said axis, a rod, means mounting the rod in alignment with the axis,a cone mounted concentrically of the axis, a carrier mounted on the rodfor reciprocal movement toward and from the cone, at least threesubstantially identical arms pivotally mounted on the carrier insubstantially equally spaced relation about the rod for movementinwardly toward the axis and outwardly therefrom having portionsengageable with the cone and fingers outwardly extended for engagementwith the cylinder, and resilient means urging the fingers inwardlytoward the axis whereby movement of the carrier toward the cone slidesthe arms endwardly thereover correspondingly pivoting the arms outwardlyto bring the fingers into positioning engagement with the cylinder.

1. A tool for positioning a work object, having an axis, with said axis disposed in a predetermined attitude with respect to a reference member, thE tool comprising an elongated rod having opposite ends; a mount, having a cam surface and a reference member engaging socket defining an axis, secured on one end of the rod; a slide member received on the rod; at least three angled arms pivotally suspended from the slide member toward the mount; said arms being mounted for movement in planes laterally disposed with respect to the rod, said planes intersecting in coincidence with the axis of the socket; and means for resiliently retaining the arms in engagement with the cam surface.
 2. The tool of claim 1 in which each arm has a control portion, having opposite ends, pivotally secured on the slide member at one of its ends and mounting a lateral extension at the other of its ends.
 3. The tool of claim 2 in which the resilient means includes tension spring interconnecting the arms.
 4. The tool of claim 3 in which a handle is borne by the rod on the end thereof remote from the mount, said handle having a striking surface facing the slide member.
 5. A tool for centering the cylindrical bore of an internal combustion engine cylinder relative to the work end of a boring machine, the tool comprising a releasible mount defining a longitudinal axis, said mount having a work end receiving socket and a conical exterior surface in axial alignment with the longitudinal axis; an elongated rod secured on the mount remote from the socket and in axial alignment therewith; a handle affixed on the end of the rod remote from the mount; a substantially cylindrical slide member received on the rod intermediate the mount and the handle; three pivotal connections mounted on the slide member defining a plane substantially normal to the rod, the connections being spaced approximately 120* in said plane equidistant from the rod; an arm individually fastened on each connection; an extension borne by each arm remote from its respective connection in right angular relation thereto; and tension springs interconnecting the arms to urge them toward the axis of the mount.
 6. A tool for centering a cylinder concentrically about a predetermined axis comprising means for supporting the cylinder for adjustable movement relative to the axis while constraining the cylinder to parallelism therewith, a cone mounted concentrically of the axis, a carrier mounted for reciprocal movement along the axis toward and from the cone, substantially identical arms pivotally mounted on the carrier in substantially equally spaced relation about the axis for movement inwardly toward the axis and outwardly therefrom having portions engageable with the cone and fingers outwardly extended for engagement with the cylinder, and resilient means urging the fingers inwardly toward the axis whereby movement of the arms endwardly of the cone correspondingly extends and retracts the fingers to and from cylinder engagement.
 7. A tool for centering a cylinder concentrically about a predetermined axis comprising means for supporting the cylinder in a plane normal to the axis for adjustable movement in the plane with the cylinder parallel to said axis, a rod, means mounting the rod in alignment with the axis, a cone mounted concentrically of the axis, a carrier mounted on the rod for reciprocal movement toward and from the cone, at least three substantially identical arms pivotally mounted on the carrier in substantially equally spaced relation about the rod for movement inwardly toward the axis and outwardly therefrom having portions engageable with the cone and fingers outwardly extended for engagement with the cylinder, and resilient means urging the fingers inwardly toward the axis whereby movement of the carrier toward the cone slides the arms endwardly thereover correspondingly pivoting the arms outwardly to bring the fingers into positioning engagement with the cylinder. 